As the continuous development of electronic technology, inverting amplifier circuits are now widely applied in electronic apparatus. Usually, these inverting amplifier circuits suffer from the Miller effect. Miller effect refers to the equivalent input capacitance of an inverting amplifier. When there is capacitance between the input end and the output end, due to the amplifying effect of the amplifier, the equivalent input capacitance will be enlarged by a factor of 1+Av wherein Av is the gain of the amplifier. This effect deteriorates the frequency performance of the amplifier.
To alleviate the Miller effect, split trench-gate metal oxide semiconductor field effect transistors (MOSFET) are designed. As shown in FIG. 1, a split trench-gate MOSFET 10 conventionally comprises two electrodes in a gate structure. A first electrode serves as the MOSFET gate electrode 101 to control the channel formation of the MOSFET, and a second electrode serves as shield electrode 102 to decrease the capacitance Cgd between drain electrode 103 and gate electrode 101. However, since the shield electrode 102 conventionally extends to surface and is further coupled to a pick-up structure 110 at a terminal region which is located at sides of MOSFET 10, it may need a relative large area to form the metal contact and pick up. Thus MOSFET 10 may cost too much die size. Meanwhile the shield electrode 102 may also generate a relative large series resistance, which limits the safe operating area (SOA) of the MOSFET.